A computer problem could force NASA to postpone next month's scheduled launch of the shuttle Discovery until 2007 to avoid having the spaceship in orbit when the clock strikes midnight on New Year's Eve.
The shuttle is due to take off from the Kennedy Space Center in central Florida on Dec. 7 on a 12-day mission to continue construction of the half-built international space station.
But if the launch is delayed for any reason beyond Dec. 17 or 18, the flight likely would be postponed until next year, officials at the space agency said Monday.
To build in an added cushion, NASA may move up the liftoff to Dec. 6.
"The shuttle computers were never envisioned to fly through a year-end changeover," space shuttle program manager Wayne Hale told journalists at a Monday briefing.
After the 2003 accident involving the space shuttle Columbia, NASA started developing procedures to work around the computer glitch. But NASA managers still do not want to launch Discovery knowing it would be in space when the calendar rolls over to Jan. 1, 2007.
The problem, according to Hale, is that the shuttle's computers do not reset to day one, as ground-based systems that support shuttle navigation do. Instead, after Dec. 31, the 365th day of the year, shuttle computers figure Jan. 1 is just day 366.
NASA is under pressure to complete at least 14 more shuttle flights to finish the space station before the aging shuttle fleet is retired in 2010.